Abstract: An electromechanical power transfer system that transfers power between a prime mover and a direct current (DC) electrical system, comprises: a permanent magnet machine (PMM) that has a permanent magnet (PM) rotor coupled to the prime mover, a stator with a multiphase alternating current (AC) winding coupled to an AC bus and a control coil with a winding that has a configuration to generate a magnetic field with flux that varies the reactance of the stator winding with the application of control coil current; a control coil current sensor for generating a control coil current signal that is representative of the level of electrical current in the control coil; an electrical current sensor for generating a DC bus current signal that is representative of the level of DC current through the DC bus; an electrical potential sensor for generating a DC bus potential signal that is representative of the level of DC potential on the DC bus; a fixed pattern active rectifier and inverter system coupled between the AC bu

Abstract: A fault-tolerant synchronisation source for excitation control of a three-phase generator system that combines point of regulation (POR) signals representing parameters comprising voltage and current for each phase at the POR to generate a fault-tolerant synchronisation signal.

Abstract: The present invention is a generator control system where each generator in the system has an associated controller. Each controller communicates generator data or information with the other controllers in the generator control system. Each of the controllers includes a digital signal processor for analyzing the generator signal from the associated generator and information from the other controllers in the generator control system. The controllers each compare their generator signal with a system average and adjust the associated generator until the generators all supply equal amounts of power to the system.

Abstract: A carrier injection sensorless (CIS) starting control system that is capable of determining the angular position and velocity of a rotor for a wound field synchronous machine at or near rest and comprises north-south pole determination and a variable or dual frequency carrier signal for improved performance throughout the start sequence for the machine.

Abstract: A control for operating an electromagnetic machine in a starting mode of operation wherein the main armature winding of the machine receives electrical power from a controllable power source during the starting mode of operation, comprises a circuit for detecting a magnitude of a parameter of power applied to the main armature winding relative to a stationary frame of reference, a position sensor for detecting rotor position of the electromagnetic machine, a converter responsive to angular position indication for converting the detected parameter magnitude into field and torque producing components relative to a rotating frame of reference, and a circuit responsive to the field and torque producing components for controlling the power source during operation in the starting mode. This control includes an igniter for igniting a prime mover.

Abstract: A detector for detecting rotor position of a brushless generator having a motive power shaft and a main generator portion having a set of armature phase windings capable of receiving AC power and developing a back EMF voltage during operation in a starting mode, includes a circuit coupled to the set of armature phase windings and capable of responding to the AC power for producing a back EMF estimate signal representing an estimate of the back EMF voltage. The detector also includes a circuit for converting the back EMF estimate signal into an indication of the angular position of the motive power shaft.

Abstract: A control unit for an inverter determines an objective function based upon harmonic content in a minimum number of the phase-to-phase AC voltages produced by the inverter and controls the switches of the inverter so as to minimize the objective function to thus control the harmonic content in the inverter output voltages.The objective function may be defined according to the following equation: ##EQU1## where W.sub.k are scaler weighting factors, A.sub.kA, A.sub.kB and A.sub.kC are the Fourier cosine coefficients of the kth harmonic of the inverter phase A, B and C outputs, B.sub.kA, B.sub.kB and B.sub.kC are the Fourier sine coefficients of the kth harmonic of the inverter phase A, B and C outputs, k is the number of the controlled odd harmonic (i.e., k=1, 3, 5 . . . ), and NHARM is the number of the highest controlled odd harmonic.

Abstract: Harmonics in the AC output power of an inverter are sensed and are compared to corresponding references to produce a plurality of errors. These errors are used to produce a harmonic waveform which is in turn used in a triangular waveform PWM pulse generator to generate PWM pulses. The PWM pulses control the inverter so as to convert DC power into AC power and so as to reduce harmonics in the AC power.

Abstract: The problem of excess size and weight resulting from the use of current sensors in a VSCF start system (10) is solved by a motor control (22) which utilizes a current estimator (68) to develop a current feedback value. The current estimator (68) is coupled to a rotor position detector (72) and an input power detector (78) and receives a signal representing motor torque angle to develop a signal representing the estimated current drawn by the motor (12).

Abstract: The problem of reducing harmonic content of AC bus voltage in a power system (10) is minimized using a controller (30) for a PWM inverter (38). The controller (30) develops a duty cycle command on a line (40) for controlling operation of the PWM inverter (38). The controller (30) develops the duty cycle command to maintain the PWM inverter output voltage at a desired level. This duty cycle command is modulated in accordance with the harmonic content evident on a DC bus (34) which supplies power to the PWM inverter (38).

Abstract: The problem of excess size and weight resulting from the use of current sensors in a VSCF start system is solved by a motor control system which utilizes a current estimator to develop a current feedback value. The current estimator is coupled to a rotor position detector and an input power detector to develop a signal representing the estimated current drawn by the motor.

Abstract: An electrically compensated constant speed drive which is speed limited so that power flow through the speed compensation link is unidirectional includes a permanent magnet generator which is interconnected with a permanent magnet motor by a power converter. The permanent magnet generator and the permanent magnet motor are controlled by first and second independent control loops. The power converter includes an AC/DC converter coupled to electrical power windings of the permanent magnet generator, a filter coupled to the output of the AC/DC converter and an inverter coupled between the filter and electrical power windings of the permanent magnet motor. The permanent magnet generator, AC/DC converter, filter and the first control loop together develop a voltage on a DC bus.